Introduction

2015-2018 Subaru WRX / STI HKS Hi-Power Cat Back Exhaust System

During dyno pulls with the 2015 CVT WRX, Mishimoto saw gains of up to 9 whp and 8 wtq using 93 octane fuel while maintaining safe AFRs on a stock tune (see additional images for dyno chart). This 2015 WRX/STI exhaust installs in under one hour and features quad 3.5″ staggered, double wall polished tips. The Mishimoto WRX/STI cat-back exhaust provides an extremely aggressive turbo and exhaust tone under acceleration and boost, giving you that sweet tone you’ve been looking for!

The Mishimoto engineers designed this WRX and STI cat-back exhaust as a four-piece design, comprised of precision TIG-welded, 304 stainless steel. This allows a smooth exhaust flow from the 3.0″ 2-bolt exhaust flange all the way through the 2.25″ Y-section. To top it off, this cat-back includes two 2.25″ V-band clamps, a 3″ exhaust-band clamp, a new 3″ 2-bolt flange gasket, and all stainless steel hardware, so you dont have to worry about rusty hardware.

Features

• 3″ to 2.25″ exhaust split helps maintain proper exhaust velocity
• Direct fit for the 2015+ Subaru WRX & STI
• Quad 3.5″ staggered double wall, polished tips
• Full 304 stainless steel mandrel-bent construction

Benefits

• Dyno-proven maximum gains of up to 9 whp and 8 wtq and peak gains of up to 4 whp and 3 wtq using 93 octane fuel while maintaining safe AFRs on the stock tune (2015 WRX w/ CVT)
• Extremely aggressive turbo and exhaust tone under acceleration and boost
• Designed with oval mufflers to prevent highway drone
• Mates with the Mishimoto, stock, or most aftermarket downpipes
• Made in the USA
• Installs in under an hour

Applications

• 2015+ WRX/STI

What’s in the Box?

• (1) Stainless Steel Mid-Pipe w/ 2-Bolt Flange
• (1) Stainless Steel Mid-Pipe to Y-Section
• (2) Stainless Steel Mufflers w/ Quad 3.5″ Staggered Double Wall Tips, Polished
• (2) 2.25″ V-Band Clamps
• (1) 3″ Exhaust-Band Clamp
• (1) 2-Bolt Flange Gasket
• (2) 3/8″-16, 1-1/2″ Hex Bolts, Stainless Steel
• (2) 3/8″-16 Serrated Flange Hex Nuts, Stainless Steel
• (2) M10 Washers, Stainless Steel

Warranty

Mishimoto Lifetime Warranty